Secreted Phosphoprotein 1 (SPP1) recombinant human protein is supplied as a lyophilized powder. This protein is suitable for use in analysis of protein structure. In general, recombinant proteins can also be used as an immunogen, as a protein standard, or in cell biology research applications.&line-break;Background: Secreted phosphoprotein 1, is a member of the osteopontin family. It is an extracellular structural protein and therefore an organic component of bone. Secreted phosphoprotein 1 is expressed in bone, although it is also expressed in other tissues. Secreted phosphoprotein 1 acts as a cytokine which is involved in enhancing production of interferon-gamma and interleukin-12 and reducing production of interleukin-10. It is essential in the pathway that leads to type I immunity. Secreted phosphoprotein 1 has been implicated as an important factor in bone remodeling. Specifically, research suggests it plays a role in anchoring osteoclasts to the mineral matrix of bones. The fact that Secreted phosphoprotein 1 interacts with multiple cell surface receptors which are ubiquitously expressed makes it an active player in many physiological and pathological processes including wound healing, bone turnover, tumorigenesis, inflammation and ischemia. Therefore, manipulation of plasma Secreted phosphoprotein 1 levels may be useful in the treatment of autoimmune diseases, cancer metastasis, osteoporosis and some forms of stress.